Once the sod is removed I dug out a shovels depth to till the soil and to mix in some gravel along with it, this is just to get rid of some other material and to help level support the bottom of the beds a little better.
Once the bed is in place I put more gravel around the perimeter and then some compost/loam mix in the middle.
After that I put the removed dirt from digging out and it will get topped with more compost/loam mix to finish it off.
Plastic beds? Steel beds? If steel, where did you get them? I made very cheap DIY beds using that wavy PVC roofing, but weed whacking the grass around them has put a few holes in them...
I'm going to be doing as you did around my beds this season and then put some mulch down to avoid this issue in the future.
Steel, I got them off of Amazon for about $160 CAD for a two pack. Doing each out of wood would have cost more. Can’t speak of longevity yet, it seems to be on the thinner gauge, but holding up well so far. Plant and plot brand.
I’m planning on some mulch or rock myself. Wife is think rock, so likely going rock haha.